Just when I thought I knew LOTS about Vegas, then a question like this comes along. No idea...where did you hear about this?
Oh gosh for the ACM's? Outside the arena I'm sure... but you probably won't be able to get there or see anything. I doubt it's open to the public. I know a friend went last year and she waited outside where they were doing the press junkets (like the radio stuff) and saw a lot of people. Looked like in the convention space. But, I mean you probably won't run into Luke Bryan or anything... probably some of the lower tier acts.